you might want to go ahead and change out your upper intake, as well as replacing your lower intake gaskets..its some pretty expensive preventative maintenance, around 120 for the upper intake, gaskets, and mine came with a new PCV valve...and then the lower gasket set was about 40 i think...so for under 200 you should be able to do it, get a Chiltons to help you out...
if you wait till it goes to replace it youll have to spend extra money on what i like to call "accessories" such as new spark plugs(the old ones will probably be fouled by coolant), 2 oil filters and a crap load of oil, not to mention the possibility of something being damaged by the overheating of when it goes
as for the oil pressure do like they said and get a mechanical gauge, i just thought id chime in on the upper..having been a victim of it myself.
2000 Oldsmobile Intrigue 3.5L DOHC V6 15x,xxx miles "The Forgotten W-Body"
shaved badges, Eclipse HU, Pioneer TS-A1370R'*, Pioneer TS-A6971R'*, 20% tint, cleared corners, Silverstar Hi'*, 9005 Low'*
Fenderwell Intake, Hi-Flow Cat, U-bend delete, GMPP Handling Kit, MOOG endlinks, and 12-inch front rotors
1996 Bonneville SE RIP 157,751 miles, totaled 8/29/05